Overheating Issues

Technical Area for all the problems you have in the garage
iansutch
Posts: 68
Joined: Thu Jun 26, 2014 12:11 pm

Re: Overheating Issues

Post by iansutch »

]
Like you say, get the simpler things checked first - pipes, fans, rheostats and temp sensors checked.
Are you hands-on or do you get someone else to get their hands dirty?![/quote]

Thanks for the comments Alan - I am learning to be hands on, hence very much appreciate the considerable knowledge base on this forum.
Karl
Posts: 766
Joined: Sat Jun 30, 2007 8:43 pm
Location: Germany

Re: Overheating Issues

Post by Karl »

I have a long aluminium tube with only two short rubber hoses(straight at front and 90 deg. at the pump)as the bottom line, if you are at it I would recommend to change it.
Regards Karl
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Roger King
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Joined: Mon Mar 19, 2007 10:29 pm
Location: St Ives, Cambs

Re: Overheating Issues

Post by Roger King »

iansutch wrote:Regarding the bottom hose and the suction effect of the pump - I think thats a very pertinent point. There is a short section of rigid tube but the hose that split was of poor quality and did not have internal wiring so I think thats a distinct possibility.
Be aware that there are two different configurations of front cover and water pump for SBFs, which give the bottom hose connection on different sides of the engine. The earlier type places the bottom hose on the RHS of the front cover, the later on the LHS. If it's all 351W stuff it should be on the LHS as the 351W was a later block, but it is perfectly possible to mount the earlier parts on this block so check first. If it is for the later style block, Gerry sells a stainless steel rigid pipe for this purpose (or you could get the right OD pipe from an exhaust supplier including a 90 and cut and weld - you can use stainless wire in a MiG. I'd weld 3 or 4 small 'blobs' to act as the beaded ends). Good idea to use pipe at the top as well, depending how long the run is. In very extreme cases it is possible for the suction to pull through the rad. Also Samco sell a flexi hose in silicone which has wire reinforcement, available in classic black.

Roger
iansutch
Posts: 68
Joined: Thu Jun 26, 2014 12:11 pm

Re: Overheating Issues

Post by iansutch »

LHS/RHS based on standing behind the engine or in front?

If I am standing behind the engine its on the LHS for me.

Thanks again Roger
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Roger King
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Joined: Mon Mar 19, 2007 10:29 pm
Location: St Ives, Cambs

Re: Overheating Issues

Post by Roger King »

iansutch wrote:LHS/RHS based on standing behind the engine or in front?

If I am standing behind the engine its on the LHS for me.

Thanks again Roger
The universal rule for which side of the car is as viewed from sitting in the driver's seat, so LHS is good, later 351W/302 (they're the same) configuration. Assuming it is the standard Hawk rad, I would buy the correct upper and lower stainless tubes from Gerry and keep the hose runs as short as possible. I actually welded a small nut in mine to take a standard rad drain petcock for ease of draining, or just a nut and bolt would do it.
iansutch
Posts: 68
Joined: Thu Jun 26, 2014 12:11 pm

Re: Overheating Issues

Post by iansutch »

Still trying to work out what my overheating issue is.

Have refreshed all hoses, replaced the faulty fan - so both are now working fine, and replaced the cap and thermostat. Checked the thermostatic fan switch and its fine.
I have flushed the radiator a few times and there are no leaks. Despite all this the engine is running hot whilst driving on short trips up and down my local A road (up to 130/140 degrees C)

How much cooler should the bottom hose be than the top. It doesn’t appear to be much cooler so I cant work out if I have a radiator issue. The only component I haven’t changed now is the water pump. (noticed a slight leak from what looks like the bottom of the water pump after driving) Would that be the next logical step? is it a tricky job?

Thanks
iansutch
Posts: 68
Joined: Thu Jun 26, 2014 12:11 pm

Re: Overheating Issues

Post by iansutch »

Well my overheating woes appear to be resolved. Have taken the car on several runs and on the road and at standstill it all seems to be under control.

The water temp gauge is reporting temp at 110 degrees C on the road and then drops to just over 100 degrees C at standstill with both fans running. Its an electronic gauge - is it likely this temp is correct or that the gauge is not too accurate?
CobStang
Posts: 320
Joined: Sat Dec 10, 2011 3:21 pm

Re: Overheating Issues

Post by CobStang »

The electronic gauges from Smiths are poor in their reliability and accuracy.
I would buy a reasonable quality hand held laser temp reader and check the engine temp against the gauge. The temp readers work best looking at a matt black hose or surface, they don't like shiny reflective surfaces.
If you have a variable fan switch with a temp scale you can to a certain extent guess coolant temp from this as well, ie if the gauge is set to 90 deg when the fan comes in look at your dash gauge and compare.
Early B.R.A. Warmed 3.9 Rover, 5 sp, 3.07 rear, Fully adjustable front suspension with AVO coilovers, 4 link rear suspension AVO coilovers and Panhard bar, Big 2 pot front calipers, rear discs, servo'd, adjustable front / rear bias, scruffy paint job !
iansutch
Posts: 68
Joined: Thu Jun 26, 2014 12:11 pm

Re: Overheating Issues

Post by iansutch »

CobStang wrote:The electronic gauges from Smiths are poor in their reliability and accuracy.
I would buy a reasonable quality hand held laser temp reader and check the engine temp against the gauge. The temp readers work best looking at a matt black hose or surface, they don't like shiny reflective surfaces.
If you have a variable fan switch with a temp scale you can to a certain extent guess coolant temp from this as well, ie if the gauge is set to 90 deg when the fan comes in look at your dash gauge and compare.
Hey thanks for the tips! They were really useful

I checked both methods and the gauge is definitely reading about 20% higher than it should which is really inaccurate. Are mechanical gauges any more accurate?
CobStang
Posts: 320
Joined: Sat Dec 10, 2011 3:21 pm

Re: Overheating Issues

Post by CobStang »

No !
The electronic gauges suffer from poor quality senders, Speedy now use a higher quality sender. You may need to remove the gauges and take any numbers off the case, phone Speedy Cables and ask for Andy Barraclough ( you may need to phone several times ) and ask him to send you the new senders to match your gauges.
Good luck.
Early B.R.A. Warmed 3.9 Rover, 5 sp, 3.07 rear, Fully adjustable front suspension with AVO coilovers, 4 link rear suspension AVO coilovers and Panhard bar, Big 2 pot front calipers, rear discs, servo'd, adjustable front / rear bias, scruffy paint job !
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